An organic light-emitting diode (OLED) is a kind of device using electrically excited fluorescence or phosphor organic compounds to emit light. Organic light-emitting diodes (OLEDs) are considered to have a broad application prospect because of advantages such as self-illumination, all solid state, broad view angle, rapid response speed and the like. Organic light-emitting diodes have been widely applied in cellphones, digital cameras, personal digital assistant (PDA), and laptop computers.
Nowadays, one mainstream display mode of organic light-emitting diode display (OLED) devices are in the structure having oxide thin film transistors (oxide TFTs), white OLED (WOLED) display, and color filters prepared on an array substrate (Color Filter on Array, COA). In order to solve the problem of threshold voltage (Vth) drift and luminance nonuniformity, a 3T1C external compensation technology is usually applied in the above mainstream display mode for driving pixels, and here the phrase “3T1C” means that a pixel circuit comprises three thin film transistors (T) and one storage capacitor (C). However, the pixel opening area of the organic electroluminescence device is quite small, leading to a reduced aperture ratio, so the luminescence intensity of the OLED has to be increased to compensate the disadvantages caused by the reduced aperture ratio. As a result, the lifetime of the OLED device is affected.